She and all the girls run to one wall, shielding their eyes. And now, as though cornered, they let out a gigantic scream, and Mary, as though infected, opens her mouth and screams with them. Gradually Abigail and the girls leave off, until only Mary is left there, staring up at the "bird," screaming madly. All watch her, horrified by this evident fit.
– Arthur Miller
The Crucible, Act 3. The stage directions give a graphic portrayal of how Abigail Williams provokes mass hysteria and sets up a chain reaction in the witch trials courtroom. She is pretending to see an imaginary demonic bird in the rafters.